The aforementioned support plate is a removable wear part which is designed to be replaced when it is worn following repeated contact with the front end of the blowing nozzle and it prevents the surface of the mold itself from being worn, with the drawbacks which this would entail.
In the known plants of the type targeted by the invention (see for example, the documents FR 2 764 544 FIGS. 1, 3, 4 and 6; FR 2 828 829 FIG. 1; FR 2 833 512 FIGS. 8 to 10; FR 2 841 495 FIGS. 2A-2C and 3; FR 2 843 714 FIGS. 1 and 3), it is known to design the support plate not only so that it receives the front end of the nozzle but also so that it defines the opening for receiving the neck of the blank to be blow-molded and that it supports said blank by its flange. Such a design had been regarded as desirable to facilitate the customizing of the plant with regard to the manufacture of containers of the same volume but with necks of different diameters: in this case, it was sufficient to change the support plates. The support plate of these known plants is therefore a metallic part of relatively large dimensions and which is, therefore, costly. The wear of this support plate in contact with the blowing nozzle occurs relatively rapidly: it therefore has to be replaced relatively often, resulting in not inconsiderable expenditure for this maintenance job, whilst the replacement of the support plates for the purposes of customization of the plant occurs less frequently than that which had been originally expected.